Other stuff I have been known to add: a bunch of spinach, diced carrots, diced celery. You could probably add any number of other vegetables.

Assemblage: Pour off the broth that comes with the seitan, but reserve it. You’ll be adding it to the soup later. Cut up the seitan (you can use a knife or just pull it apart with your fingers — it’s gluten!) into bite-sized pieces. Mince the garlic. Heat the olive oil in whatever pot or saucepan you usually use to make soup. Add the garlic and seitan. Saute them until the garlic is softened, throw in the herbes de provence. If you’re adding carrots and celery, add them now, and saute them until they’ve softened. (The nature of seitan is such that you can’t really over-saute it, or at least I haven’t managed to personally.) Gradually add the reserved seitan broth, then the other broth. (Because I am not a vegetarian despite my fondness for seitan, I often use chicken broth.) Bring the mixture to a boil, then add the orzo. Cook until the orzo is done, usually, oh, twenty minutes or so.